Conclusion: Fulvic acid can reduce the ability of graphene oxide to enhance the toxicity of environmental pollutants.
Title: Facilitated Bioaccumulation of Perfluorooctanesulfonate in Common Carp (Cyprinus carpio) by Graphene Oxide and Remission Mechanism of Fulvic Acid
Type of Document: Peer-reviewed journal article
Takeaway: Graphene oxide (GO) can adsorb harmful substances such as perfluorooctane sulfonate (PFOS) which, upon consumption by aquatic creatures like carp can cause toxicity. However, fulvic acid can competitively adsorb on graphene oxide and reduce its ability to enhance the toxicity of pollutants. For example, GO could carry PFOS to penetrate the intestine cells. There herein, PFOS absorption, especially via intestine, and the uptake rate coefficient (ku) were greatly enhanced, leading to distinctly promoted bioaccumulation of PFOS in fish. However, FA could facilitate the flocculation of GO in the intestine, and also accelerate excretion of GO-PFOS complex. Thus, in the presence of FA, PFOS absorption was reduced and the promotion effect of GO on PFOS accumulation was remitted.
Link: https://sci-hub.ru/https://pubs.acs.org/doi/10.1021/acs.est.6b02100
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Conclusion: Humic acid can reduce the toxicity of graphene oxide to aquatic life.
Title: The effects of humic acid on the toxicity of graphene oxide to Scenedesmus obliquus and Daphnia magna
Type of Document: Peer-reviewed journal article
Takeaway: Graphene oxide (GO) induced significant toxicity to algae S. obliquus and water flea D. magna, and the median lethal concentrations for acute toxicity were 20.6 and 84.2 mg/L, respectively. However, humic acid (HA) mitigated the acute toxicity of GO to S. obliquus and D. magna by 28.6% and 32.3%, respectively, and mitigated the chronic toxicity of GO to D. magna.
Link: https://sci-hub.ru/10.1016/j.scitotenv.2018.08.280
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Conclusion: Humic acid can reduce the toxicity of some forms of graphene oxide to aquatic life.
Title: Humic acids alleviate the toxicity of reduced graphene oxide modified by nanosized palladium in microalgae
Type of Document: Peer-reviewed journal article
Takeaway: Humic acid (HA) increased the defects and dispersity of palladium-modified reduced graphene oxide (Pd/rGO) and reduced cellular damage and oxidative stress responses in microalgae triggered by Pd/rGO, thereby reducing the biological toxicity of Pd/rGO.
Link: https://www.sciencedirect.com/science/article/pii/S0147651322006340
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Conclusion: Humic acid can reduce the toxicity of graphene oxide to plants and the environment.
Title: Humic acid acts as a natural antidote of graphene by regulating nanomaterial translocation and metabolic fluxes in vivo
Type of Document: Peer-reviewed journal article
Takeaway: Humic acid (HA) reduces the toxicity of graphene oxide (GO) nanoparticles in plants by enhancing its compartmentalization in plant cell vacuoles. Thus, HA has the potential to significantly alter the nanotoxicity of GO in the environment.
Link: https://sci-hub.ru/10.1021/es5012548
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Conclusion: Humic acid reduces the toxicity of graphene oxide to zebrafish.
Title: Mitigation in Multiple Effects of Graphene Oxide Toxicity in Zebrafish Embryogenesis Driven by Humic Acid
Type of Document: Peer-reviewed journal article
Takeaway: Graphene oxide (GO) is highly toxic to zebrafish during embryo formation, causing a significant hatching delay and cardiac edema, and altering the protein secondary structure. In this study, humic acid (HA) significantly relieved the above adverse effects. HA reduced the interactions between GO and the fish embryo, and mitigated damage by regulating the morphology, structures and surface negative charges of GO. HA also altered the uptake and deposition of GO and decreased the aggregation of GO in embryonic yolk cells and deep layer cells. Furthermore, HA mitigated the mitochondrial damage and oxidative stress induced by GO.
Link: https://sci-hub.ru/10.1021/acs.est.5b02220
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Conclusion: Fulvic acid- and humic acid-coated surfaces are able to attach graphene oxide, which can help in the removal of this toxic agent.
Title: Interactions of graphene oxide nanomaterials with natural organic matter and metal oxide surfaces
Type of Document: Peer-reviewed journal article
Takeaway: Deposition rates of graphene oxide (GO) were generally higher on fulvic acid- and humic-acid coated surfaces than on the metal oxide surface investigated in this study, indicating that most of GO will be deposited on fulvic acid- and humic acid-coated surfaces in the aquatic environment.
Link: https://sci-hub.ru/https://pubmed.ncbi.nlm.nih.gov/25026416/
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Conclusion: Humic acid reduces the toxicity of graphene and graphene oxide on aquatic life in multiple ways.
Title: Humic acid mitigated toxicity of graphene-family materials to algae through reducing oxidative stress and heteroaggregation
Type of Document: Peer-reviewed journal article
Takeaway: Adverse effect of graphene-family materials (GFMs) on aquatic organisms has attracted increasing attention. However, natural organic matter may alter GFMs-induced toxicity. This work demonstrated that GFMs-induced toxicity to algae was highly mitigated by humic acid (HA), and the antagonistic degree followed the order of reduced graphene oxide (rGO)> graphene oxide (GO)> graphene (G). The alleviation in membrane damage by HA was a main mechanism for the observed toxicity mitigation, through decreasing both oxidative stress and GFMs-algae direct contact. The direct contact was lowered by weakened GFMs-algae heteroaggregation (for rGO and G) and enhanced steric hindrance (for GO, rGO and G).
Link: https://sci-hub.ru/https://pubs.rsc.org/en/content/articlelanding/2019/en/c9en00067d
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Conclusion: Humic acid reduces the toxicity of graphene oxide on freshwater algae.
Title: Humic acid alleviates the ecotoxicity of graphene-family materials on the freshwater microalgae Scenedesmus obliquus
Type of Document: Peer-reviewed journal article
Takeaway: In this study, humic acid (HA) mitigated the toxicity of graphene family materials (GFMs), including graphene oxide, on algae through three possible mechanisms: (1) reducing the contact of GFMs with algae cells through regulating the structures and surface negative charges of GFMs; (2) mitigating physical penetration and damage through decreasing the deposition of GFMs on cells by interacting with HA; (3) reacting as an antioxidant with intracellular reactive oxygen species (ROS) and extracellular hydroxyl radical (OH). This work provides useful information for the environmental toxicity of GFMs and the possible antidotal mechanisms in the presence of HA.
Link: https://sci-hub.ru/https://pubmed.ncbi.nlm.nih.gov/29407839/